Control apparatus for drilling wells



Oct. 11, 1938. J. E. BRANTLY CONTROL APPARATUS FOR DRILLING WELLS I Filed Dec. 8, 1934 2 Sheets-Sheet 1 INVENTOR. JHMERA/VTLK ATTORNEYS 2 Sheets-Sheet 2 J. E. BRANTLY CONTROL APPARATUS FOR DRILLING WELLS Filed Deo. 8,- 1934 .Oct 11, 1938.

` INVENTOR. w//N/PAA/ rz. K

ATTORNEYS BY gw..

l Patented oa. 11, 193s I CONTROL APPARATUS FOR DBILLING WELLS .lohn E. Brantly, Birmingham, Ala., anlgnor to Drilling and Exploration Company, Inc., Dover, Del., a corporation of Delaware Application December s, 1934, semina. 156,696

'I Claims.

My invention relates to a hydraulic mechanism for controlling the feed of a drill stem to a well being drilled.

In the drilling of wells, particularly wells for petroleum, a heavy drill stem and'drilling apparatus extending into the well are suspended on a cable running over crown pulleys on the top of a derrick and thence to a winding drum near the base or floor of thederrick. As the drilling of the well proceeds, the drill stem is gradually lowered into the well by permitting or vcausing the winding drum to rotate to permit the cable to gradually unwind. 'I'he unwinding of the cable and consequent lowering, of the drill stem must be such as to avoid throwing too great a proportion of the weight o`f the drill stem onto the rock or earth at the bottom of the well, because this may cause the drilling point to sink too deeply into the rock and become wedged or stuck therein so that it cannot be rotated or moved and may become broken. For the best results the drum should be unwound at such a rate for given conditions in the well as to support a portion ,of the weight of the drill stem on the cable and throw the remaining part of the weight of the drill stem, in accordance with particular rock formation encountered, onto the bottom of the well. Y

In a hydraulic control for the unwinding of A$0 the drum, the force or energy imparted to the drum shaft by the weight of the drill and its attached parts supported by the cable is used to force water or other liquid against a resistance. To avoid sudden changes in the weight carried by the cable and consequently to avoid such changes in the weight of the drill supported in the bottom of the well, the movement of the fluid should be as smooth as possible and free the characteristics of the earth through which the drill penetrates vary at different depths, it is alsonecessary that the resistance may be accurately and promptly adjusted to maintain a 5 predetermined proportion of the weight suspended by the cable and to enable the driller to have constantly an indication of `the weight thus supported.

In my invention hydraulic means are provided 5o whereby the liquid is forced by the unwinding of the drum4 in a smooth, even fashion, and in which the resistance or pressure thus generated may be accurately determined and controlled. Also the apparatus is such that the unwinding control may be easily and quickly changed and from intermittent stoppages or pulsations. As

the drum rotated in a' winding direction to lift the drill from the well.

The various features of the invention are illustrated in the accompanying drawings lin which' Fig. 1 is a diagrammatic sketch showing the re- 5 lation of the control apparatus and winding drum to the der rlck and drill stem; Fig. 2 is a side view on a larger scale of the winding drum and hydraulic control device; Fig. 3 is a plan view of the drum and control apparatus; and Fig. 4 is 10 i a planyiew partly in section of a portion of the control mechanism.

In my invention a drill stem I0 is supported by a cable II that passes over a crown pulley I2 on a derrick I3 and is then wound on a drum 15 I4. The drill stem may be of any suitable type, such as used for rotary drilling, and any of the suitable drilling rigs may be employed. As the drill III graduallyv bores into the earth to form the well, it is lowered by the rotation of the drum 20 I4 to unwrap. additionallengths of the cable II. The gradual steady unwrapping of the 'cable II rotates thev drum I4 with a considerable force and this force is opposed and taken up in pumping or otherwise driving water or other liquid 25 against a selected pressure. The driving connections between the drum I4 and a pump 'I5 may be of any suitable type, preferably having a speed multiplying or power reducing transmission. In the accompanying drawings this trans- 30 mission is shown by way of example as comprising a sprocket wheel I6 rotatably mounted on the drum shaft and, in one direction of rotation, engaging a clutch I6a, keyed to the drum. I4. The sprocket wheel I6 when engaged by the clutch 35 I6a drives a sprocket chain I1 which in turn \drives a sprocket wheel I8 of a g'ear box I9.

In the gear box I9 are a number of gears indicated at 20 and 2| of Fig. 4 which serves as speed multiplying and power reducing means. 40 For example, in one installation the power was reduced in a ratio of about to 1 and a speed proportionately increased. The end gear 2i of the gear box at I9' is supported on a shaft 22 to which it may be clutched by means of a clutch 4.5 23. It meshes directly with a gear 24 on the crank shaft 25 of the pump I5 which is preferablya multi-cylinder double acting pump, six cylinders being shown by way of example.

Liquid such as water or oil is supplied from a i0 storage tank or reservoir 20 through a pipe 21 to the'pump I5 and is then forced thereby through .piping 28 to a plurality of control valves 23, 30,. 3|, 32 and 33 arranged in parallel and connecting the pipe 23 to a return pipe 34 leading back to the tank or reservoir 26. The control valves 28-33 are of different sizes. For example, in one illustration they rangedfrein $4; inch to 2 inch valves, the valve E3 being a 1/4 inch valve, valve 32 being a 1/2 inch valve, valve 3i being 'a 3A inch valve, valve 30 being a 1 inch valve and valve 2Q a 2-ineh valve. A master control valve 35 is aiso provided on the pipe 28 through which ow of liquid from the pump I5 may be entirely shut off. An indicator 36 is also mounted on a pipe 28 to indicate the nui-:i pressurev maintained therein. The valve assembly 29-33 and the indicator 36 may be mounted in an'y desired position enabling the control te be placed Within' the derrick convenient to the driller so that it may be' instantly at his command. In operating the apparatus the unwinding of the drum may be entirely stopped by closing the valve 35. This completely stops the flow of fluid from the pump I5 and there ;r stops the rotation of the drum to which the -pump is positively connected by the transmission mechanism. By closingv all of the valves 2li- 33, ex-cept a selected valve, and

then opening the valve 35, liquid is permitted to flow from the pump I5 through the connecting pipes to the tank 28 and backto the pump under a resistance '-.vhich controls the' speed of tine pump and consequently the rate of unwinding of the drum I4. For example, when onlv the valve 33 is open a maximum of resistance is offered and the drum I4 unwinds very slowly.

'Ihe pressure indicated by the indicator 36, when all of the valves 28-33 are closed, is a measure of the weight of the drill stem and any ldrop in this pressure as any of the valves29-33 is opened and the fluid circulating is'an indication of the proportionate weight of the drill stem removed from the supporting cable and thus transferred' to the bottom of the well being drilled. 'I'he indicator 36 therefore gives an immediate and accurate indication to the driller of the pressure being exerted by the drill stem on the earth formations atthe bottom of the well. For a given type of earth or rock formation the valve 29-36' may be regulated from the derrick iloor to provide the exact drill stem pressure required. Also due to the multiplication of speed from the drum I4 to the pump I5 and to the use of several cylinders whereby pulsations are evenly distributed throughout a pumping cycle the reactions of the pump to the'drum I4 are smoothed out and a very steady resistance to the rotation of the drum is provided. To indicate the rate of drilling or the rate at which the drill is lowered into the well a speed indicator shovm diagrammatically at 3l, Figs. 3 and 4, is provided on the shaft 22. By indicating the revolutions per minute or other period of time this speed indicator gives an accurate measure oi the rate of lowering of the drill stem.

When .it is desired to lower the drill stem rapidly into the well the clutch 23 is moved to declutch the gear El from the shaft 22 thereby throwing the pump out of operation. When the drill stem is to be lifted out of the well, the drum shaft is driven from the drawworks of the drilling apparatus in the usual manner and, in the event that the gear 2l is not deciutched from the shaft 22, the sprocket wheel I6 will override the clutch I6a and the reducing mechanism and pump will not be operated. In case of anv emergency, however, t le drill stem can be raised by declutching the ciutch 23. The shaft is then driven by means of a motor 38 which is connected to the shaft 22 by a suitable flexible coupiing 39. The mctor thus drives the sprocket wheel I8 through the shaft 22 and gear train l 2|, `21|. Thus, the same gear box and driving connections between the drum I4 and the gear box I8, the construction of the gear box itself and the type of pump |5 are given merely by way of example of suitable transmission mechanisms and pumping apparatus. As these are mechanical constructions for which alternatives are well kncwn, it will be understood that other alternative arrangements of transmission mechanism and other types of pumping apparatus than those specifically described may be used. With the above arrangement of the various elements of the combination there is provided a control mechanism for the unwinding of the drum that enables the drill to be smoothly lowered without changes in the effective weight or pressure imparted to the drilling end and in which this weight is under the convenient and immediate control of the driller and whereby `the apparatus may be quickly shifted to hoist the drill instead of lowering it.

What I claim is:

1. A brake for drilling apparatus comprising a drum, a drill suspending cable wrapped on said drum, a speed multiplying transmission means driven by said drum, a pump driven by said transmlssien means, a fluid circuit in. series with said pump and having a plurality of throttle vaives arranged in parallel in said circuit.

2.A brake for drilling apparatus comprising a drum,a drill suspending cable Wrapped on said drum, a speed multiplying transmission means driven by said drum, a pump driven by said transmission means, a uid circuit in series with said pump and having a plurality of throttle valves arranged in parallel in said circuit and an indicator in said circuit in advance of said throttie valves.

3. A brake for drilling apparatus comprising a' drum, a drill suspending cable wrapped on said drum, a speed multiplying transmission means driven by said drum, a double Aacting multi-cylinder pump driven by said transmission means, a fluid circuit in series with said pump and having a plurality of thrc-ttle valves arranged in parallel in said circuit.

4. A brake for drilling apparatus comprising a drum, a drill suspending cable Wrapped en said drum, a speed multiplying transmission means driven by said drum, a pump driven by said transmission means, a fluid circuit in series with said pump and having a plurality of throttle valves arranged in paraliel in said circuit and a speed indicator connected to said transmission mechanism.

5. A brake for drilling apparatus comprising a drum, a drill suspending cable wrapped on said drum, a speed multiplying transmission means driven by said drum, a pump driven by said transmission means, a fluid circuit in series With said pump and having a plurality of throttle valves arranged in parailel in said circuit and a driving motor and means to selectively connect said motor to said transmission mechanism.

6. A srake for drilling apparatus comprising a drum, a drill suspending cable wrapped on said drum, a speed multiplying transmission means driven by said drum, a pump driven by said 4 said pump and having a plurality of throttle valves arranged in parallel in said circuit, a driving motor for said transmission and means for disconnecting the driving means from the transmission to the pump.

7. 'A brake for drilling apparatus comprising a drum, ajd'rill suspending cable wrapped on said drum, aspeed/ multiplying transmission, engaging means driving said transmission from said drum, said means disengaging when the direction of rotation is reversed, a pump driven by said transmission, a fluid circuit in series with said pump yand having a plurality of throttle valves arranged in parallel in said circuit, and a driving motor, and means to selectively connect said motor to said transmission mechanism.

JOHN E. BRANTLY. 

